Thoughts from the intersection of science, pseudoscience, and conflict.

genetics

As longtime readers here know, I’m endlessly fascinated by the ways in which people attempt to misuse genetics to legitimize pseudoscientific ideas.

Today I’m going to write about one example which I’ve been meaning to address for some time: pseudoscientific claims about the genetic distinctiveness of the Paracas peoples. (Please note that I don’t usually show images of Native American remains on this blog, but there was no other way to illustrate the details of this issue. Under the cut is an embedded video of the unwrapping of a Paracas mummy, as well as a photo with the mummy under its wrappings.)

My colleagues and I have just published a paper on the genetic diversity and population history of contemporary Iñupiat peoples (the indigenous inhabitants of the North Slope of Alaska) in the American Journal of Physical Anthropology. It’s open-access for at least a few months, so you can read it in its entirety here, our collaborator Dr. Anne Jensen ‘s thoughts on it here, and Archaeology Magazine’s article on the paper here. I’ve also summarized our findings below.

In a series of recent posts I and several others have strongly criticized Nicholas Wade’s recent book “A Troublesome History”, which purports to show that human races are biologically meaningful categories, characterized by different behavioral tendencies (which have resulted in different degrees of socio-political success). Now 139 professors with expertise in genetics, human biology, biological anthropology, and evolution have added their voices to this discussion, criticizing Wade’s book in a strongly worded letter that appears in the New York Times today. The full text of their letter can be found here. Organized by Grahm Coop, Michael Eisen, Rasmus Nielsen, Molly Przeworski, and Noah Rosenberg, the signatories include many of the leading researchers in human genomics (a full list of signatories and their affiliations can be found here).

Several of the authors are people whose research Mr. Wade cited approvingly in his book as supporting his thesis, such as Dr. Sarah Tishkoff, Dr. David Reich, and Dr. Noah Rosenberg (lead author of the 2002 paper that Mr. Wade uses as the primary evidence for his conception of genetically distinct races).

The letter was spearheaded by five population geneticists who had informally discussed the book at conferences, says co-organizer Rasmus Nielsen of the University of California, Berkeley. “There was a feeling that our research had been hijacked by Wade to promote his ideological agenda,” Nielsen says. “The outrage … was palpable.”

The authors don’t mince words:

Wade juxtaposes an incomplete and inaccurate account of our research on human genetic differences with speculation that recent natural selection has led to worldwide differences in I.Q. test results, political institutions and economic development. We reject Wade’s implication that our findings substantiate his guesswork. They do not.

We are in full agreement that there is no support from the field of population genetics for Wade’s conjectures.

This letter is highly inconvenient for Mr. Wade, making it clear that the senior researchers in the fields from which he’s trying to marshal support categorically reject his storytelling and bad science. Nor can he continue to make the (untrue) argument that critiques of his book are largely politically based, and conducted mainly by social scientists. A strong blow has been dealt to scientific racism today.

UPDATE: Mr. Wade has issued a statement responding to the letter. He starts out reasserting the position I claimed above that he can’t continue to hold:

“This letter is driven by politics, not science. I am confident that most of the signatories have not read my book and are responding to a slanted summary devised by the organizers.

As no reader of the letter could possibly guess, “A Troublesome Inheritance” argues that opposition to racism should be based on principle, not on the anti-evolutionary myth that there is no biological basis to race. Unfortunately many social scientists have long denied that there is a biological basis to race. This creed, prominent throughout the academic world, increasingly impedes research. Biologists risk damaging their careers if they write explicitly about race.

In yesterday’s post on the subject, Mr. David Dobbs described who several of the authors are:

Yale’s Kenneth Kidd, who is one of the world’s most respected population geneticists, a central figure in establishing the field, and another co-author on the 2002 Rosenberg paper.

Stanford’s Jonathan Pritchard, another co-author on that paper and the researcher whose lab designed the ”Structure“ genetic analysis software that created the ”clustering“ data Wade says supports his argument.

Jun Li and Richard Myers, the lead and senior authors of a 2008 paper, ”Worldwide Human Relationships Inferred from Genome-Wide Patterns of Variation,” that, as I noted in my review, Wade misrepresented as supporting his argument.

These and the other signatories of the letter are the leaders in the field of human population genetics. They do not shy away from research and writing about human genetic variation. Mr. Wade is wrong to imply that they are being intimidated by cultural anthropologists. The fact that they agree on a single statement (on anything) is extraordinary and should be treated seriously.

Further, I suspect that more people on that list have read his book than he believes, simply because I’ve talked to them. In fact, Jerry Coyne, one of the signers of the letter has read it twice. (I encourage you to read his thoughts on the subject at the link above).

Disturbingly, Mr. Wade appears to be adopting the methodology of his “HBD” followers in claiming that evolution requires acceptance of his view of race. The data do not support that position, and saying so doesn’t make any of us anti-evolution, no matter how loudly he says it.

He goes on:

These attacks have included repeated assertions that the book is scientifically inaccurate, a charge for which I have seen no basis. In the same vein, this letter issues general charges without supporting evidence.

You might find this American Anthropological Association-sponsored debate between Agustin Fuentes and Nicholas Wade illuminating:

ETA (8/10/14): I mistakenly listed only Dr. Coop as the organizer of the letter. I’ve edited to add the names of the other professors who organized and wrote it. My sincere apologies for the oversight.

In recent weeks, Nicholas Wade’s book A Troublesome Inheritance has been soundly criticized on the basis of his misunderstanding (or misrepresentation) of the statistical methods used to study human genetic variation (see Jeremy Yoder’s critique here, Chris Smith’s here, Joseph Graves’ here, and mine here ), his misunderstanding of evolution (see Michael Eisen’s critique here, and Eric Michael Johnson’s here ), and his misunderstanding of human biological variation (see Greg Laden’s critique here, Agustin Fuentes’ critique here, and Jon Marks’ here ). These criticisms–all from biologists and biological anthropologists– can be boiled down into a single statement: Mr. Wade’s book is scientifically unsound.

His responses thus far (to those of us who published in the Huffington Post) have failed to engage any of the substantive issues that have been raised. Instead, he dismissed our standing for discussing this issue, calling me a “postdoctoral student” (A science journalist should be aware that postdocs aren’t students), and dismissing Dr. Fuentes’ and Dr. Marks’ research background and credentials (as if biological anthropologists were not scientists). I have not seen any response yet to the numerous other critiques from biologists that have appeared elsewhere (many listed in the previous paragraph), which raise many of the same concerns.

Mr. Wade may feel that he can ignore the substantive critiques of his book by scientists. But can he do the same for fellow science journalists? David Dobbs’ review of Mr. Wade’s book appeared in the New York Times Book Review this past Sunday (the online version can be read here). It is not favorable. Mr. Dobbs calls the book “deeply flawed, deceptive, and dangerous.”

In discussing the study (critiqued by most of us above) that Mr. Wade claims supports the genetic basis for three (or is it five?) “continental races”, Mr. Dobbs notes that the paper itself

“directly contradicts Wade’s argument. Yet he baldly claims the study as support. And he does this sort of thing repeatedly: He constantly gathers up long shots, speculations and spurious claims, then declares they add up to substantiate his case. The result is a deeply flawed, deceptive and dangerous book.”

“Wade demonstrates how a lucid, well-written, selective presentation of evidence — eloquent, elegant cherry-picking — can convince smart people of pernicious ideas that seem scientific, but which science does not support. Much of the sleight of hand in this book will not be evident to people who don’t know the field. In some cases one has to read a specific paper cited by Wade to recognize that he thoroughly misrepresents its findings.”

I encourage you to go read both of Mr. Dobbs’ critiques. It will be interesting to see how Mr. Wade responds.

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Update: Here are a few other critiques worth mentioning:

Nicholas Wade has a problem. Although his new book, “A Troublesome Inheritance: Genes, Race and Human History”, appears to be selling well, he’s not encountering the praise that he expected from biologists for “courageously” freeing them from the “intimidating social scientists” on the subject of race).

Plus ça change, plus c’est la même chose

What is he arguing? I go over this briefly in my recent piece on the Huffington Post, and in much greater detail here on this blog, but essentially Wade is using patterns of human variation in populations as a justification for claiming that race is a valid, biological taxonomic category. He goes on to speculate (and that’s really the only word for it, since his claims are unsupported by the preponderance of scientific evidence) that these racial differences determine behavioral differences and thereby explain why some civilizations have historically been more successful economically and politically than others. (You can guess which races he’s talking about; his speculation happens to coincide neatly with traditional stereotypes.)

Wade claims that all critics of this viewpoint are motivated by political concerns and ignore data showing that races are genetically distinct enough to be meaningful taxonomic categories of humans. His book relies particularly upon one genomics study to support this point. In his words (emphasis mine):

Raff and Marks take issue with one of these surveys, Rosenberg et al. 2002, which used a computer program to analyze the clusters of genetic variation. The program doesn’t know how many clusters there should be; it just groups its data into whatever target number of clusters it is given. When the assigned number of clusters is either greater or less than five, the results made no genetic or geographical sense. But when asked for five clusters, the program showed that everyone was assigned to their continent of origin. Raff and Marks seem to think that the preference for this result was wholly arbitrary and that any other number of clusters could have been favored just as logically. But the grouping of human genetic variation into five continent-based clusters is the most reasonable and is consistent with previous findings. As the senior author told me at the time, the Rosenberg study essentially confirmed the popular notion of race.

It’s not a question of logic, but rather what the data show. Rosenberg et al. (2002)’s paper did not analyze or identify just 5 clusters, but rather it considered 1-20 clusters. What Wade is omitting from his paragraph above (and also from his book) is that Rosenberg and colleagues never presented any statistical justification for the choice of 5 clusters over any other number.

Here are the specifics of my criticism, which I posted in response to a commenter on my blog. (If you’re not interested in the statistical refutation of Wade’s argument, feel free to skip this paragraph. I hope Wade takes the time to read it, though). Continue reading →

“…for he has no right to give names to objects which he cannot define.” –Charles Darwin

Do “races” exist as meaningful biological categories? Physical anthropologists and human biologists have been studying race (i.e., blacks vs. whites, or Europeans vs. Asians) for centuries. For most of that time, they subscribed to the perspective that race was a taxonomic category, and they sought to identify the biological characteristics (such as cranial shape or skin color) that characterized and defined these different groups. This perspective assumed that each individual was a member of a single racial category, that the differences between racial categories were biological, and that these categories were predictive of other traits (such as ancestry, temperament, intelligence, or health).

But it gradually became clear that this understanding was not scientifically sound. Groupings of people by skin color did not produce the same result as groupings of people by skull shape, nor of blood type. Furthermore, as scientists began to study human variation with the tools of genetics (in the process creating my fields, anthropological genetics and human population genetics), it became apparent that human genetic variation does not divide humans into a few discrete groups. There are virtually no sharp boundaries, either with physical features or with patterns of genetic diversity, that show where one population “ends” and the next “begins”. Continue reading →

This is the second post in a series discussing the recent publication of a 12,500 year old genome from Montana. You can find the first post here.

In the weeks following the publication of the complete genome from a Clovis child, there’s been a lot of press coverage of this study and its possible implications. I want to discuss a bit of the media coverage on this subject, since it raises issues that I think science journalists need to consider more carefully.

First of all, to recap the major findings of the original study (discussed in more detail at the link above):
1. Anzick-1, the 12,500 year old Clovis child whose genome Rasmussen and colleagues sequenced, is very closely related to living and ancient Native Americans.
2. Anzick-1 is more closely related to Siberians than other Eurasian groups.
3. Anzick-1 is more closely related to Central and South American Native American groups than to some North American groups.
4. The results from Anzick-1’s genome fit with the scientific consensus about the peopling of the Americas. This consensus encompasses the results of decades of archaeological, genetic, and paleoclimate research.

Unfortunately, several press reports chose to find controversy in a decidedly non-controversial story by giving undue weight to problematic “alternative” explanations of Native American origins, including the Solutrean hypothesis, and other “European contributions” to Native American ancestry.

Last Wednesday, Dr. Morton Rasmussen of the Natural History Museum of Denmark and his colleagues announced that they had completely sequenced the genome of an infant boy, buried ~12,600 years ago in Montana. A few weeks earlier, I’d been approached by an editor at Nature, who asked me if I and my mentor Deborah Bolnick would be interested in writing a companion paper that would analyze and contextualize their results. We agreed, and the paper was published in last week’s issue, alongside Rasmussen et al.’s work. Because it’s (unfortunately) behind a paywall, I’d like to summarize what we said in that paper for non-scientists. There are a lot of things to talk about with regard to this study, including a consideration of ethical issues and the media’s response, so I’m likely going to do several posts on it. This first post is mainly a discussion of how we interpret the results.

These points, and many others along the same lines, were made by Mr. Gavin McInnes, author of “How To Be a Man” in a recent discussion of masculinity on the Huffington Post. His argument is based on a suite of assumptions common in our culture. It often forms the basis of misogynist arguments against feminism. Basically:

1. Evolution has made men naturally more “aggressive and tough”, and women naturally more “compassionate and domestic”.

2. Therefore in the modern world, as in past societies, men are the natural breadwinners, and women the natural caretakers of the home/children.

3. Going against these gender norms, as feminism has done in the last few decades, is going against nature, and disrespectful of the importance of childcare!

According to Mr. McInnes, women who work outside the home are “forced to pretend to be men. They’re feigning this toughness. They’re miserable.” You’ll hear a lot of people agreeing with this line of reasoning. But is it scientifically based? Continue reading →